FROM THIS EPISODE

President Barack Obama's announcement that the last American soldiers would leave Iraq by the end of this year capped a momentous week in which he could also take credit for helping dispatch Colonel Moammar Gadhafi. Guest host Terrence McNally explores what this will mean in next year's elections. Also, moderate Islamists claim victory in Tunisian elections, and a new study headed by a former skeptic offers confirmation of global climate change.

Banner image: President Barack Obama talks with Prime Minister Nouri al-Maliki of Iraq during a secure video teleconference in the Situation Room of the White House, Oct. 21, 2011. Official White House Photo by Pete Souza

President Barack Obama's on a foreign policy roll: the death of Moammar Gadhafi, the assassinations of Anwar Awlaki in Yemen and Osama bin Laden in Pakistan. Obama's withdrawal from Iraq and the successful NATO air campaign in Libya reaffirmed his credentials as a wartime leader. But conventional wisdom holds that none of this will matter because his political fortunes will be determined by the US economy. How will voters weigh his foreign policy victories against a sour economy? Will Republican candidates still try to make the case that he's weak on national security?

A scientist known for his skepticism over climate change released a new study this month with surprising results. UC Berkeley astrophysicist Richard Muller and a team of other scientists recently set out to test whether measurements of Earth's temperature are too flawed to show that the Earth is warming. The analysis of more than 1.6 billion temperature measurements led him to write in a recent op-ed in the Wall Street Journal, "You should not be a skeptic, at least not any longer. Global warming is real." Muller is a complicated character, writes Andrew Revkin in the Dot Earth blog for the New York Times.

As the Arab Spring turns to autumn, the latest chapter in the unfolding story takes place in Tunisia where international observers hailed the elections for a new constituent assembly. Results Tuesday indicate a first-place finish for the moderate Islamic Party, Ennahda, which now begins talks to form a unity government. David Kirkpatrick, Cairo Bureau Chief for the New York Times reports from Tunis.